Time question

Ruby
#1

I am writing a small piece that will include a date that needs to be
compared to the current time.

EX. a = Time.now
b = db_cert_date + (72 months)

  if(a < b)
      do something
  elsif(a > b)
      do something else
  else
      do this
  end

I am looking for the best way to add 72 months onto an old date and
then compare it with the current date. Does anyone have any ideas?

Thanks in advance

#2

joep wrote:

I am writing a small piece that will include a date that needs to be
compared to the current time.

EX. a = Time.now
b = db_cert_date + (72 months)

Rails’s ActiveSupport package lets you say some_date + 72.months. It’s
that
simple; the secret unit of exchange is probably seconds.

If this were Brand X, using another platform’s low-level library would
be
eternal torment, but this is Ruby, so just try require ‘active_support’!

#3

On Sep 10, 10:03 am, Phlip [email protected] wrote:

If this were Brand X, using another platform’s low-level library would be
eternal torment, but this is Ruby, so just try require ‘active_support’!

–
Phlip

Only problem is I’m not using rails. Just straight ruby as a cgi.

#4

On 9/10/07, joep [email protected] wrote:

      do something else

How 'bout DateTime?
The DateTime#>> operator means “return a new Date object that is n
months
later than the current one.”

For your code to work db_cert_date would have to be a DateTime, too.

irb(main):018:0> a = DateTime.now
=> #<DateTime: 35342700409548349/14400000000,-1/6,2299161>
irb(main):019:0> puts a.strftime(’%m/%d/%Y’)
09/10/2007
=> nil
irb(main):020:0> b = a >> 72
=> #<DateTime: 35374265209548349/14400000000,-1/6,2299161>
irb(main):021:0> puts b.strftime(’%m/%d/%Y’)
09/10/2013
=> nil

#5

On 9/10/07, joep [email protected] wrote:

that

You don’t have to be using rails you just need the active_support gem
installed.

gem install activesupport

After that just require ‘active_support’ as Phlip said.

–
“Hey brother Christian with your high and mighty errand, Your actions
speak
so loud, I can’t hear a word you’re saying.”

-Greg Graffin (Bad Religion)

#6

On Tue, Sep 11, 2007 at 01:35:08AM +0900, Phlip wrote:

If this were Brand X, using another platform’s low-level library would be
eternal torment, but this is Ruby, so just try require ‘active_support’!

Depending on how accurate you actually want, active_support’s 72.months
assumes 30 days in a month. Here’s a quick comparison of adding 72
months in different libraries:

% cat time-test.rb
#!/usr/bin/env ruby
require 'rubygems'
require 'active_support'
require 'chronic'

today_time = Time.now
today_dt   = DateTime.now
format     = "%Y-%m-%d %H:%M:%S"
puts "Calculate the date of 72 months from today  :

#{today_time.strftime(format)}"
puts “ActiveSupport (today (Time) + 72.months) : #{(today_time +
72.months).strftime(format)}”
puts “ActiveSupport (today (Time) + 6.years) : #{(today_time +
6.years).strftime(format)}”
puts “Chronic.parse ‘72 months from now’ :
#{Chronic.parse(‘72 months from now’).strftime(format)}”
puts “DateTime.now >> 72 : #{(today_dt >>
72).strftime(format)}”

% ruby time-test.rb
Calculate the date of 72 months from today  : 2007-09-10 11:32:14
ActiveSupport (today (Time) + 72.months)    : 2013-08-09 11:32:14
ActiveSupport (today (Time) + 6.years)      : 2013-09-09 23:32:14
Chronic.parse '72 months from now'          : 2013-09-10 11:32:14
DateTime.now >> 72                          : 2013-09-10 11:32:14

As you can see, there is some disparity. From my perspective, the only
ones of
these that are actually correct are the Chronic and the DateTime ones.

Is there a really good date calculation library in ruby that I’m
missing?

enjoy,

-jeremy

#7

On Sep 10, 12:59 pm, Rob B. [email protected]
wrote:

  b = db_cert_date + (72 months)

then compare it with the current date. Does anyone have any ideas?
[email protected] Hide quoted text -

  • Show quoted text -

Thanks Rob. This did work quite the way I wanted it to but I think
with a little playing around I can get it. Thanks for the direction.

#8

On Sep 10, 2007, at 12:25 PM, joep wrote:

  else
      do this
  end

I am looking for the best way to add 72 months onto an old date and
then compare it with the current date. Does anyone have any ideas?

Thanks in advance

If db_cert_date was a Date, you could do:

b = db_cert_date >> 72

-Rob

Rob B. http://agileconsultingllc.com
[email protected]

#9

joep wrote:

eternal torment, but this is Ruby, so just try require ‘active_support’!

–
Phlip

Only problem is I’m not using rails. Just straight ruby as a cgi.

Phlip’s point was that you can use active_support without using rails:

gem install activesupport

cheers,
mick

#10

On Tue, Sep 11, 2007 at 01:25:04AM +0900, joep wrote:

I am writing a small piece that will include a date that needs to be
compared to the current time.

If you require date, you can do something like:

if DateTime.now < (Date.parse(some_date_string.to_s) >> 72 )

puts ‘Pay up, chump!’
end

There may be a more elegant way, but this would get the job done.